To date, no microscope is available on Earth that can view an object as small as an atom. Yet, scientists have put out the structure of each atom, their bonding to form molecules and even various levels in which electrons exist. If such a technology does not exist, then how are people so sure that electrons actually revolve around a nucleus? Fluorescence microscopy using ultra narrow bandpass filters have made this possible due to a peculiar characteristic of electrons.

Microscopy – detecting electrons

Around a nucleus, electrons reside in various energy levels. When excited, these jump to higher levels and later come back to its original state emitting photons. The light energy released is exactly equal to the difference in the two levels and this very concept can be used to image the structure of atoms.

Now, this initial excitation is generally done with ultraviolet or laser lights. To excite a particular electron, light of a particular frequency must be send and precision to the utmost level is primary. This is where optical filters with steep bandpass are used.

The concept of bandpass is simple. Circuitry is designed in such a manner that will allow an input signal of a particular frequency range to be reflected on its output. Any signal lying beyond this range is truncated and output is zero. In case of fluorescent microscopy, the input is laser, of which a particular band is allowed to pass and excite an atom.

The level of precision achieved is the USP of such filters. The edges are steep and transmission is maximum. The best possible applications are in DNA sequencing where a particular order of nucleotides is used for DNA matching. Each nucleotide has to be excited with light of a particular frequency which can be achieved with custom made filters.

Hard coated filters – a necessary soft coating replacement

Such optical or light filters come in two types – soft and hard coated. Although soft coated ones serve the purpose of sharp bandpass quite well, hard coated ones are known for its increased durability and improved performance. Results have shown that transmission is increased by almost 90% when hard coated ones are considered as soft coating replacement filters.

In case of Notch filters, for instance, laser is continuously supplied and only a particular band is restricted. The concept is just the opposite of bandpass but requires the same level of precision. In such applications, hard coated ones serve better as optical filters for improved performance.

Now, while selecting a filter, remember that both OEM and aftermarkets work well. But the former one comes with an added benefit – custom OEM filters. Since the makers of the bought device are also the manufacturer of filters as well, it can be custom made to pass a particular range of band or notch the same. The rate of transmission can also be customized accordingly.

Hence, optics based microscopy is that instrument that is bringing a new field of research and developments into light across all sectors. Imagine just how many things have been made possible with Raman spectroscopy. For all these, the precision of ultra narrow bandpass filters is important as results will depend on what frequency of light is sent for test. Obtain filters from makers using the latest technology and go ahead with groundbreaking research.